Abstract: The present disclosure provides an image sensor, a color filter array, and a preparation method thereof. The method includes: etching a photosensitive array substrate to form a plurality of strip-shaped first color filters, arranged at intervals in a first direction, a width direction thereof being parallel to the first direction; and etching the photosensitive array substrate to form block-shaped second and third color filters, the second and third color filters being disposed within the intervals of the first color filters and distributed in a second direction alternately, wherein the first direction is perpendicular to the second direction. An RGB arrangement manner different from a traditional manner is proposed from the perspective of layout design, thereby breaking a single RGB layout arrangement manner and providing more space for RGB design.